/*
 * Copyright 2010-2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *  http://aws.amazon.com/apache2.0
 *
 * or in the "license" file accompanying this file. This file is distributed
 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing
 * permissions and limitations under the License.
 */
package com.ibm.cloud.objectstorage.services.s3.transfer;

import com.ibm.cloud.objectstorage.AmazonClientException;
import com.ibm.cloud.objectstorage.AmazonServiceException;
import com.ibm.cloud.objectstorage.event.ProgressListener;

/**
 * Represents an asynchronous upload to or download from Amazon S3.
 * Use this class to check a transfer's progress,
 * add listeners for progress events,
 * check the state of a transfer,
 * or wait for the transfer to complete.
 * <p>
 * See {@link TransferManager} for more information about creating transfers.
 *
 * @see TransferManager#upload(String, String, java.io.File)
 * @see TransferManager#upload(com.ibm.cloud.objectstorage.services.s3.model.PutObjectRequest)
 */
public interface Transfer {

    /**
     * Enumeration of the possible transfer states.
     */
    public static enum TransferState {
        /** The transfer is waiting for resources to execute and has not started yet. */
        Waiting,

        /** The transfer is actively uploading or downloading and hasn't finished yet. */
        InProgress,

        /** The transfer completed successfully. */
        Completed,

        /** The transfer was canceled and did not complete successfully. */
        Canceled,

        /** The transfer failed. */
        Failed;
    }

    /**
     * Returns whether or not the transfer is finished (i.e. completed successfully,
     * failed, or was canceled).
     *
     * @return Returns <code>true</code> if this transfer is finished (i.e. completed successfully,
     *         failed, or was canceled).  Returns <code>false</code> if otherwise.
     */
    public boolean isDone();

    /**
     * Waits for this transfer to complete. This is a blocking call; the current
     * thread is suspended until this transfer completes.
     *
     * @throws AmazonClientException
     *             If any errors were encountered in the client while making the
     *             request or handling the response.
     * @throws AmazonServiceException
     *             If any errors occurred in Amazon S3 while processing the
     *             request.
     * @throws InterruptedException
     *             If this thread is interrupted while waiting for the transfer
     *             to complete.
     */
    public void waitForCompletion()
            throws AmazonClientException, AmazonServiceException, InterruptedException;
    
    /**
     * Waits for this transfer to finish and returns any error that occurred, or
     * returns <code>null</code> if no errors occurred.
     * This is a blocking call; the current thread
     * will be suspended until this transfer either fails or completes
     * successfully.
     *
     * @return Any error that occurred while processing this transfer.
     * 		   Otherwise returns <code>null</code> if no errors occurred.
     *
     * @throws InterruptedException
     *             If this thread is interrupted while waiting for the transfer
     *             to complete.
     */
    public AmazonClientException waitForException() throws InterruptedException;
    
    /**
     * Returns a human-readable description of this transfer.
     *
     * @return A human-readable description of this transfer.
     */
    public String getDescription();

    /**
     * Returns the current state of this transfer.
     *
     * @return The current state of this transfer.
     */
    public TransferState getState();

    /**
     * Adds the specified progress listener to the list of listeners
     * receiving updates about this transfer's progress.
     *
     * @param listener
     *            The progress listener to add.
     */
    public void addProgressListener(ProgressListener listener);

    /**
     * Removes the specified progress listener from the list of progress
     * listeners receiving updates about this transfer's progress.
     *
     * @param listener
     *            The progress listener to remove.
     */
    public void removeProgressListener(ProgressListener listener);

    /**
     * Returns progress information about this transfer.
     *
     * @return The progress information about this transfer.
     */
    public TransferProgress getProgress();
    
    /**
     * @deprecated Replaced by {@link #addProgressListener(ProgressListener)}
     */
    @Deprecated
    public void addProgressListener(com.ibm.cloud.objectstorage.services.s3.model.ProgressListener listener);

    /**
     * @deprecated Replaced by {@link #removeProgressListener(ProgressListener)}
     */
    @Deprecated
    public void removeProgressListener(com.ibm.cloud.objectstorage.services.s3.model.ProgressListener listener);
}
